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Impacts of the annual cycle of background SST in the tropical Pacific on the phase and amplitude of ENSO
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作者 Song Jiang Congwen Zhu Ning Jiang 《Atmospheric and Oceanic Science Letters》 2025年第1期12-17,共6页
The dominant annual cycle of sea surface temperature(SST)in the tropical Pacific exhibits an antisymmetric mode,which explains 83.4%total variance,and serves as a background of El Niño-Southern Oscillation(ENSO).... The dominant annual cycle of sea surface temperature(SST)in the tropical Pacific exhibits an antisymmetric mode,which explains 83.4%total variance,and serves as a background of El Niño-Southern Oscillation(ENSO).However,there is no consensus yet on its anomalous impacts on the phase and amplitude of ENSO.Based on data during 1982-2022,results show that anomalies of the antisymmetric mode can affect the evolution of ENSO on the interannual scale via Bjerknes feedback,in which the positive(negative)phase of the antisymmetric mode can strengthen El Niño(La Niña)in boreal winter via an earlier(delayed)seasonal cycle transition and larger(smaller)annual mean.The magnitude of the SST anomalies in the equatorial eastern Pacific can reach more than±0.3◦C,regulated by the changes in the antisymmetric mode based on random sensitivity analysis.Results reveal the spatial pattern of the annual cycle associated with the seasonal phase-locking of ENSO evolution and provide new insight into the impact of the annual cycle of background SST on ENSO,which possibly carries important implications for forecasting ENSO. 展开更多
关键词 annual cycle SST anomaly Antisymmetric mode ENSO
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Annual variation of adult survival of a south-temperate House Wren population in Argentina
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作者 Gustavo J.Fernandez Mariana E.Carro Paulo E.Llambías 《Avian Research》 SCIE CSCD 2024年第2期229-237,共9页
Identifying factors affecting the survival of individuals is essential for understanding the evolution of life-history traits and population dynamics.Despite numerous studies on this subject in north-temperate environ... Identifying factors affecting the survival of individuals is essential for understanding the evolution of life-history traits and population dynamics.Despite numerous studies on this subject in north-temperate environments,there is a lack of equivalent studies at similar latitudes in the south.Here,we used a 14-year dataset of capture,banding,and resighting to estimate the annual variation in the apparent adult survival probability of a south-temperate population of House Wrens(Troglodytes aedon bonariae).We evaluated temporal variation in sur-vival and the effect of environmental(climatic)and demographic variables(adult abundance,total number of fledglings produced during each breeding season)on survival estimators.We found that the probability of adult survival decreased as the abundance of breeding adults increased.This density-dependent effect could be related to the resident lifestyle of southern House Wrens,which could determine an intense competition for territories and resources that ultimately would affect their survival. 展开更多
关键词 annual variation CJS DENSITY-DEPENDENCE SURVIVAL Troglodytes aedon bonariae
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The changes in the annual distribution of mountain runoff during the period of 1965-2018 in Hexi Corridor,Northwest China
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作者 Yan Luo ZhiXiang Lu +2 位作者 Qi Feng Meng Zhu JinBo Zhang 《Research in Cold and Arid Regions》 CSCD 2024年第2期73-83,共11页
The annual distribution characteristics of river runoff in arid regions have significant implications for water resource stability and management.Based on the mountain runoff data from 1965 to 2018,this study examines... The annual distribution characteristics of river runoff in arid regions have significant implications for water resource stability and management.Based on the mountain runoff data from 1965 to 2018,this study examines the annual change characteristics of monthly runoff of the Shiyang River Basin,Heihe River Basin,and Shule River Basin in the Hexi Corridor,Northwest China.Many indexes are used and analyzed,including the coefficient of variance,the complete regulation coefficient,the concentration degree and concentration period,the magnitude of change,the skewness coefficient,and the kurtosis coefficient of the annual distribution curves.The results reveal the following:(1)The inhomogeneity of annual runoff distribution in the Taolai River and the rivers to the west of it,except the Shiyou River,show an increasing trend.Conversely,the inhomogeneity of the rivers to the east of the Taolai River generally show a downward trend,but the coefficient of variance value is still very high.(2)In the Shiyang River Basin,the annual distribution of the concentration period is characterized by a relatively discrete pattern.Conversely,the Heihe River Basin exhibits a relatively concentrated pattern,and the distribution pattern of the Shule River Basin is quite different.Notably,all concentration periods in the three basins have shifted backward after the 2000s.(3)The Shiyang River Basin exhibits disordered annual distribution curves of runoff in different years.In contrast,the Heihe River Basin presents a typical‘single-peak’pattern with a prominent right-skewed.The Shule River Basin has regular distribution curves,with a gradually significant‘double-peak’pattern from east to west.Overall,there has been a slight change in runoff in the Shiyang River Basin,while the Heihe River Basin and Shule River Basin have experienced significant increases in runoff.The annual distribution curves of runoff in the Liyuan River and the rivers to the east of it exhibit a gentle peak pattern,and the appearance probability of extreme runoff during the year is low.Conversely,the rivers to the west of the Liyuan River,excluding the Danghe River,display a sharp peak and thick tail pattern,indicating that the appearance probability of extreme runoff during the year is high.These findings have practical implications for the planning and management of water resources in the Hexi Corridor.Moreover,they provide a solid foundation for predicting future changes in regional water resources. 展开更多
关键词 Hexi Corridor Inland rivers Mountain runoff annual distribution characteristics of runoff
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Fragipan Horizon Changes Using Annual Ryegrass and Other Admendments
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作者 Lloyd Murdock Anastasios Karathanasis +2 位作者 Dottie Call Dana L. Dinnes Amitava Chatterjee 《Open Journal of Soil Science》 2024年第6期388-397,共10页
A greenhouse experiment was conducted involving intact fragipan soil cores of 50 cm thickness after removing the topsoil horizons. The cores were maintained in moist condition throughout the experiment and received se... A greenhouse experiment was conducted involving intact fragipan soil cores of 50 cm thickness after removing the topsoil horizons. The cores were maintained in moist condition throughout the experiment and received several treatments with various amendments for different periods ranging from 9 to 17 months. The amendments included annual ryegrass or Festulolium residues, powder limestone and various humate compounds alone or in combination with the grass residues. The results suggested a significant effect of ryegrass and Festulolium in reducing penetration resistance into the top 10 cm of the fragipan within 9 - 17 months, particularly when used in combination with certain humate materials such as Leonardite. Apparently, this is the result of the release of certain soluble organic compounds from the plant residues or the humate amendments that increase the solubility of Si and Al associated with the fragipan brittleness, thus decreasing the density of the compacted fragipan material. 展开更多
关键词 Fragipan Fragipan Horizon Fragipan Soils Changing the Fragipan annual Ryegrass Changes Fragipan Festulolium Changes Fragipan Amendments That Change the Fragipan
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Wind risk and mitigation calculator framework for determining the wind annualized risk for single- and multi-family homes to support resilient community decision-making
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作者 Ayat Al Assi Rubayet Bin Mostafiz +6 位作者 Fatemeh Orooji Arash Taghinezhad Melanie Gall Robert V.Rohli Christopher T.Emrich Carol J.Friedland Eric Johnson 《Resilient Cities and Structures》 2024年第4期21-33,共13页
Communicating risks and mitigation benefits associated with natural hazards such as wind to the general public is challenging given the location-dependency of parameters and the complexity of the problem.Web tools pla... Communicating risks and mitigation benefits associated with natural hazards such as wind to the general public is challenging given the location-dependency of parameters and the complexity of the problem.Web tools play a crucial role in educating residents,decision-makers,and stakeholders regarding potential wind hazard losses to,for example,residential buildings.However,a notable gap exists on the practical incorporation of mitigation actions within these tools.This gap hampers the collective awareness and understanding among stakeholders,communities,and citizens regarding the tangible advantages of mitigation strategies in reducing wind-related risks.Furthermore,there exists a need to elucidate the functionality and objectives of these tools in a more accessible manner.This study aims to present and outline the wind risk and mitigation calculator tool(WRMCT)within the Hazardaware platform,which is an address-based risk assessment tool.This tool,developed for 196 counties in the Gulf of Mexico coastal area,facilitates users’education of potential risks and benefits associated with mitigation strategies.WRMCT enables users to access location-specific wind risk and interactively suggests potential mitigation actions along with economic savings to support informed decisions and residential risk reduction.WRMCT intends to enhance users’ability to make informed decisions,take proactive measures in mitigating wind hazards,and contribute to the development of resilient,residential communities. 展开更多
关键词 Wind risk assessment Average annual loss(AAL) Public information technology Wind mitigation Wind loss analysis Catastrophic risk modeling Resilient communities
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Analysis on the Variations of Annual Runoff Distribution in the Weihe Basin 被引量:5
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作者 杨美临 范晓梅 《Meteorological and Environmental Research》 CAS 2010年第6期91-94,共4页
With the impact of climate change and the increasing intensity of human activities,the hydrological regime had changed,including annual runoff distribution,which was related with water resources management and ecologi... With the impact of climate change and the increasing intensity of human activities,the hydrological regime had changed,including annual runoff distribution,which was related with water resources management and ecological construction. Based on the monthly runoff data for more than 40 years of the Beidao,Xianyang,Huaxian station on Weihe Basin,the annual distribution characteristics of runoff were studied. Several indices related to attributes of uneven,concentrate degree and variation amplitude were calculated,and the results showed that there had obvious fresh and drought seasonal changes in 1990s. The annual runoff distribution had changed a lot,mainly because of runoff decrease in the wet season. The Huaxian station,which locates at the upper reaches,had a higher unevenness,concentration and relative variation rate than that of the Beidao and Xianyang station. 展开更多
关键词 Weihe Basin RUNOFF annual distribution China
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Horizontal Distribution and Annual Variations of Fecal Coliform Bacteria in Luoyuan Bay 被引量:2
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作者 蔡雷鸣 《Marine Science Bulletin》 CAS 2010年第1期48-58,共11页
Fecal Coliform Bacteria (FCB) of marine waters was monitored in Luoyuan Bay from January, 2003 to December, 2005. The results showed that number of FCB in marine water samples ranged from no detection ( 〈2 cfu/100... Fecal Coliform Bacteria (FCB) of marine waters was monitored in Luoyuan Bay from January, 2003 to December, 2005. The results showed that number of FCB in marine water samples ranged from no detection ( 〈2 cfu/100 mL) to 540 cfu/100 mL in Luoyuan Bay. Values of FCB during August to October were significantly higher than those during January to April during three year period. Monthly changes of FCB values at each year period were mainly due to monthly precipitation. In addition, compared with FCB values in difference sample sites, values of FCB in Bay-heed were significantly higher than those in middle of bay and Bay-mouth, Luoyuan Bay. However, values of FCB in Bay-mouth were significantly less than those in middle of bay. The ratios to the par of FCB in 2003, 2004, and 2005 years were 100%, 98.0%, and 97.9%, respectively. Therefore, we considered that the pollution of FCB of surface marine water in Luoyuan Bay was not serious. 展开更多
关键词 Luoyuan Bay fecal coliform bacteria horizontal distribution annual variations
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Variations in the annual cycle of the East Asian monsoon and its phase-induced interseasonal rainfall anomalies in China 被引量:4
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作者 JIANG Song ZHU Congwen JIANG Ning 《Atmospheric and Oceanic Science Letters》 CSCD 2020年第4期316-322,共7页
The East Asian monsoon(EAM)exhibits a robust annual cycle with significant interannual variability.Here,the authors find that the EAM annual cycle can be decomposed into the equinoctial and solstitial modes in the com... The East Asian monsoon(EAM)exhibits a robust annual cycle with significant interannual variability.Here,the authors find that the EAM annual cycle can be decomposed into the equinoctial and solstitial modes in the combined sea level pressure,850-hPa low-level wind,and rainfall fields.The solstitial mode shows a zonal pressure contrast between the continental thermal low and the western Pacific subtropical high,reaching its peak in July and dominating the East Asian summer monsoon.The equinoctial mode shows an approximate zonal contrast between the low-level cyclone over the east of the Tibetan Plateau and the western Pacific anticyclone over the east of the Philippines.It prevails during the spring rainy season in South China and reaches its peak in April.The interannual variations of the lead–lag phase of the two modes may result in the negative correlation of rainfall anomalies in North China between spring and fall and in South China between winter and summer,which provides a potential basis for the across-seasonal prediction of rainfall.The warm phase of ENSO in winter could give rise to the reverse interseasonal rainfall anomalies in South China,while the SST anomaly in the Northwest Pacific Ocean may regulate the rainfall anomaly in North China. 展开更多
关键词 annual cycle East Asian monsoon interannual variability
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Quantification of relationship between annual daily maximum temperature and annual daily maximum rainfall in South Australia
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作者 YE Qianping AHAMMED Faisal 《Atmospheric and Oceanic Science Letters》 CSCD 2020年第4期286-293,共8页
The empirical relationship between annual daily maximum temperature(ADMT)and annual daily maximum rainfall(ADMR)was investigated.The data were collected from four weather stations located in Adelaide,South Australia,f... The empirical relationship between annual daily maximum temperature(ADMT)and annual daily maximum rainfall(ADMR)was investigated.The data were collected from four weather stations located in Adelaide,South Australia,from 1988 to 2017.Due to the influence of sea surface temperature on rainfall and temperature,the distance from the weather station to the sea was considered in the selection of weather stations.Two weather stations near the sea and two inland weather stations were selected.Three non-parametric statistical tests(Kruskal–Wallis,Mann–Whitney,and correlation)were applied to perform statistical analysis on the ADMT and ADMR data.It was revealed that the temperature and rainfall in South Australia varies according to weather station location.The distance from the sea to the weather station was found to have limited influence on temperature and rainfall.Meanwhile,with the 0.05 level of significance,the association between ADMT and ADMR near sea stations is not as significant as the association between the two inland weather stations.It is relatively unrealistic to use ADMR to predict ADMT,or vice versa,since their correlation is not statistically significant(Spearman’s rank correlation coefficient:−0.106). 展开更多
关键词 annual daily maximum rainfall annual daily maximum temperature kruskal–Wallis Mann–Whitney correlation
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Annual Runoff and Sediment in Duhok Reservoir Watershed Using SWAT and WEPP Models
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作者 Mohammad E. Mohammad Nadhir Al-Ansari Sven Knutsson 《Engineering(科研)》 2016年第7期410-422,共14页
Estimation of runoff volume and sediment load is the main problem that affects the performance of dams due to the reduction in the storage capacity of their reservoirs and their effect on dam efficiency and operation ... Estimation of runoff volume and sediment load is the main problem that affects the performance of dams due to the reduction in the storage capacity of their reservoirs and their effect on dam efficiency and operation schedule. The simulation models can be considered for this purpose if the continuous field measurements are not available. Soil and Water Assessment Tool (SWAT) and Water Erosion Prediction Project (WEPP) models were applied to estimate the annual runoff volume and sediment load for Duhok Dam Reservoir in north of Duhok/Iraq for the period 1988-2011. The estimated annual runoff volume varied from 2.3 to 34.7 MCM for considered period. Those values were affected by rainfall depth, intensity and runoff coefficient. The resultant annual runoff coefficient for the studied area ranged from 0.05 to 0.35 (average was 0.18) causing an average runoff volume of about 14 MCM. The results of sediment routing indicated that the values of sediment yields varied from 50 to 1400 t/km2/year depending on sub basin properties. The average annual sediment load from the whole watershed is about 120 × 10<sup>3</sup> ton. The estimated total sediment arrived to Duhok Reservoir for the considered period 1988-2011 was about 2.9 × 10<sup>6</sup> ton. The results indicate that both models gave reasonable results in comparison with measured values. Based on statistical criteria, the results of both models are close to gather. 展开更多
关键词 annual Runoff annual Sediments Duhok Dam SWAT Model WEPP Model
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The Role of Changes in the Annual Cycle in Earlier Onset of Climatic Spring in Northern China 被引量:13
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作者 钱诚 符淙斌 严中伟 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2011年第2期284-296,共13页
Climatic changes in the onset of spring in northern China associated with changes in the annual cycle and with a recent warming trend were quantified using a recently developed adaptive data analysis tool, the Ensembl... Climatic changes in the onset of spring in northern China associated with changes in the annual cycle and with a recent warming trend were quantified using a recently developed adaptive data analysis tool, the Ensemble Empirical Mode Decomposition. The study was based on a homogenized daily surface air temperature (SAT) dataset for the period 1955–2003. The annual cycle here is referred to as a refined modulated annual cycle (MAC). The results show that spring at Beijing has arrived significantly earlier by about 2.98 d (10 yr)-1, of which about 1.85 d (10 yr)-1 is due to changes in the annual cycle and 1.13 d (10 yr)-1 due to the long-term warming trend. Variations in the MAC component explain about 92.5% of the total variance in the Beijing daily SAT series and could cause as much as a 20-day shift in the onset of spring from one year to another. The onset of spring has been advancing all over northern China, but more significant in the east than in the west part of the region. These differences are somehow unexplainable by the zonal pattern of the warming trend over the whole region, but can be explained by opposite changes in the spring phase of the MAC, i.e. advancing in the east while delaying in the west. In the east of northern China, the change in the spring phase of MAC explains 40%–60% of the spring onset trend and is attributable to a weakening Asian winter monsoon. The average sea level pressure in Siberia (55°–80°N, 50°–110°E), an index of the strength of the winter monsoon, could serve as a potential short-term predictor for the onset of spring in the east of northern China. 展开更多
关键词 spring onset Ensemble Empirical Mode Decomposition modulated annual cycle Asian winter monsoon global warming
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On Multi-Timescale Variability of Temperature in China in Modulated Annual Cycle Reference Frame 被引量:16
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作者 钱诚 Zhaohua WU +1 位作者 符淙斌 周天军 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2010年第5期1169-1182,共14页
The traditional anomaly (TA) reference frame and its corresponding anomaly for a given data span changes with the extension of data length. In this study, the modulated annual cycle (MAC), instead of the widely us... The traditional anomaly (TA) reference frame and its corresponding anomaly for a given data span changes with the extension of data length. In this study, the modulated annual cycle (MAC), instead of the widely used climatological mean annual cycle, is used as an alternative reference frame for computing climate anomalies to study the multi-timescale variability of surface air temperature (SAT) in China based on homogenized daily data from 1952 to 2004. The Ensemble Empirical Mode Decomposition (EEMD) method is used to separate daily SAT into a high frequency component, a MAC component, an interannual component, and a decadal-to-trend component. The results show that the EEMD method can reflect historical events reasonably well, indicating its adaptive and temporally local characteristics. It is shown that MAC is a temporally local reference frame and will not be altered over a particular time span by an exten-sion of data length, thereby making it easier for physical interpretation. In the MAC reference frame, the low frequency component is found more suitable for studying the interannual to longer timescale variability (ILV) than a 13-month window running mean, which does not exclude the annual cycle. It is also better than other traditional versions (annual or summer or winter mean) of ILV, which contains a portion of the annual cycle. The analysis reveals that the variability of the annual cycle could be as large as the magnitude of interannual variability. The possible physical causes of different timescale variability of SAT in China are further discussed. 展开更多
关键词 modulated annual cycle the Ensemble Empirical Mode Decomposition climate anomaly climate normal variability of surface air temperature in China
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Temporal and spatial variation of annual mean air temperature in arid and semiarid region in northwest China over a recent 46 year period 被引量:24
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作者 Chen, ShaoYong Shi, YuanYuan +1 位作者 Guo, YuZhen Zheng, YanXiang 《Journal of Arid Land》 SCIE 2010年第2期87-97,共11页
We analyzed the 1961-2006 mean surface air temperature data of 138 stations in China’s northwest arid and semi-arid areas(CNASA),to measure climate change in terms of annual mean air temperature changes.We used metho... We analyzed the 1961-2006 mean surface air temperature data of 138 stations in China’s northwest arid and semi-arid areas(CNASA),to measure climate change in terms of annual mean air temperature changes.We used methods of linear regression analysis,multinomial fitting,Empirical Or-thogonal Function(EOF),Rotated Empirical Orthogonal Function(REOF),Mann-Kendall,Glide T-examination,wavelet analysis and power spectrum analysis.The results show that(1) the warming rate of the annual mean air temperature in CNASA was 0.35oC/10a during the 1961-2006 study period.Some places in the west part of Xinjiang and east part of the Qinghai plateau,which is impacted by the terrain of leeward slope,exhibit smaller increasing trends.However,the majority of region has shown distinct warming in line with general global warming;(2) The standard deviation of the annual mean temperature distribution is non-uniform.The south Xinjiang and east Qinghai-south Gansu areas show relatively small standard deviations,but the inter-annual variation in annual mean air temperature in the greater part of the region is high;(3) Inner Mongolia,Shaanxi,Gansu,Ningxia and Tarim Basin are the areas where the temperature changes are most sensitive to the environment.The degree of uniformity in annual mean air temperature increase is higher in the arid and semi-arid area.From the early 1970s,the trend in tempera-ture changed from a decrease to an increase,and there was a marked increase in mean temperature in 1986.After that mean temperature went through a period of rapid increase.The entire area’s 10 hottest years all occurred in or since the 1990s,and 90% of various sub-districts’ hottest years also occurred after 1990.The process of temperature change appears to have a roughly 5-year and a 10-year cycle;(4) An-nual mean air temperature variation has regional differences.In Inner Mongolia-Xinjiang and Shaanxi-Gansu-Ningxia-Qinghai areas,the temperature variation in their northern areas was very different from that in their southern areas;(5) Using the REOF method we divided the region into 4 sub-regions:the Northern region,the Plateau region,the Southern Xinjiang region and the Eastern region.The region’s annual mean air temperature transition has regional differences.The Plateau and Southern Xinjiang re-gions got warmer steadily without any obvious acceleration in the rate of warming.The Northern region’s warming started about 5-years earlier than that of the low latitude Eastern region.The ’Startup region’ of the Qinghai-Tibet Plateau,appears to undergo temperature changes 3 to 10 years earlier than the other regions,and exhibits inter-decadal variations 1 to 2 years ahead of the other regions. 展开更多
关键词 northwest area of China annual mean air temperature climatic warming
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Impact assessment of climate change and human activities on annual highest water level of Taihu Lake 被引量:9
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作者 Qing-fang HU Yin-tang WANG 《Water Science and Engineering》 EI CAS 2009年第1期1-15,共15页
The annual highest water level of Taihu Lake (Zm) is very significant for flood management in the Taihu Basin. This paper first describes the inter-annual and intra-annual traits of Zm from 1956 to 2000. Then, using... The annual highest water level of Taihu Lake (Zm) is very significant for flood management in the Taihu Basin. This paper first describes the inter-annual and intra-annual traits of Zm from 1956 to 2000. Then, using the Mann-Kenall (MK) and Spearman (SP) nonparametric tests, the long-term change trends of area precipitation and pan evaporation in the Taihu Basin are determined. Meanwhile, using the Morlet wavelet transformation, the fluctuation patterns and change points of precipitation and pan evaporation are analyzed. Also, human activities in the Taihu Basin are described, including land use change and hydraulic project construction. Finally, the relationship between Zm, the water level of Taihu Lake 30 days prior to the day of Zm (Z0), and the 30-day total precipitation and pan evaporation prior to the day of Zm (P and E0, respectively) is described based on multi-linear regression equations. The relative influence of climate change and human activities on the change of Zm is quantitatively ascertained. The results demonstrate that: (1) Zm was distinctly higher during the 1980-2000 period than during the 1956-1979 period, and the 30 days prior to the day of Zm are the key phase influencing Zm every year; (2) P increased significantly at a confidence level of 95% during the 1956-2000 period, while the reverse was true for E0; (3) The relationship between Zm, P and E0 distinctly changed after 1980; (4) Climate change and human activities together caused frequent occurrences of high Zm after 1980; (5) Climate change caused a substantially greater Zm difference between the 1956-1979 and 1980-2000 periods than human activities. Climate change, as represented by P and E0, was the dominant factor raising Zm, with a relative influence ratio of 83.6%, while human activities had a smaller influence ratio of 16.4%. 展开更多
关键词 climate change human activities annual highest water level Taihu Lake
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Long-term Trend and Fractal of Annual Runoff Process in Mainstream of Tarim River 被引量:18
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作者 XU Jianhua CHEN Yaning +1 位作者 LI Weihong DONG Shan 《Chinese Geographical Science》 SCIE CSCD 2008年第1期77-84,共8页
Based on the time series data from the Aral hydrological station for the period of 1958-2005,the paper re-veals the long-term trend and fractal of the annual runoff process in the mainstream of the Tarim River by usin... Based on the time series data from the Aral hydrological station for the period of 1958-2005,the paper re-veals the long-term trend and fractal of the annual runoff process in the mainstream of the Tarim River by using the wavelet analysis method and the fractal theory.The main conclusions are as follows:1)From a large time scale point of view,i.e.the time scale of 16(24)years,the annual runoff basically shows a slightly decreasing trend as a whole from 1958 to 2005.If the time scale is reduced to 8(23)or 4(22)years,the annual runoff still displays the basic trend as the large time scale,but it has fluctuated more obviously during the period.2)The correlation dimension for the annual runoff process is 3.4307,non-integral,which indicates that the process has both fractal and chaotic characteris-tics.The correlation dimension is above 3,which means that at least four independent variables are needed to describe the dynamics of the annual runoff process.3)The Hurst exponent for the first period(1958-1973)is 0.5036,which equals 0.5 approximately and indicates that the annual runoff process is in chaos.The Hurst exponents for the second(1974-1989)and third(1990-2005)periods are both greater than 0.50,which indicate that the annual runoff process showed a long-enduring characteristic in the two periods.The Hurst exponent for the period from 1990 to 2005 indi-cates that the annual runoff will show a slightly increasing trend in the 16 years after 2005. 展开更多
关键词 annual runoff wavelet FRACTAL Tarim River
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Documented changes in annual runoff and attribution since the 1950s within selected rivers in China 被引量:8
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作者 LIU Lu-Liu DU Jian-Jun 《Advances in Climate Change Research》 SCIE CSCD 2017年第1期37-47,共11页
To enable local water resource management and maintenance of ecosystem integrity and to protect and mitigate against flood and drought, it is necessary to determine changes in long-term series of streamflow and to dis... To enable local water resource management and maintenance of ecosystem integrity and to protect and mitigate against flood and drought, it is necessary to determine changes in long-term series of streamflow and to distinguish the roles that climate change and human disturbance play in these changes. A review of previous research on the detection and attribution of observed changes in annual runoff in China shows a decrease in annual runoff since the 1950s in northern China in areas such as the Songhuajiang River water resources zone, the Liaohe River water resources zone, the Haihe River water resources zone, the Yellow River water resources zone, and the Huaihe River water resources Zone. Furthermore, abrupt changes in annual runoff occurred mostly in the 1970s and 1980s in all the above zones, except for some of the sub-basins in the middle Yellow River where abrupt change occurred in the 1990s. Changes in annual runoff are found to be mainly caused by climate change in the western Songhuajiang River basin, the upper mainstream of the Yangtze River, and the western Pearl River basin, which shows that studies on the impact of climate change on future water resources under different climate change scenarios are required to enable planning and management by agencies in these river basins. However, changes in annual runoff were found to be mainly caused by human activities in most of the catchments in northern China (such as the southern Songhuajiang River, Liaohe River, Haihe River, the lower reach and some of the catchments within the middle Yellow River basin) and in middle-eastern China, such as the Huaihe River and lower mainstream of the Yangtze River. This suggests that current hydro-climatic data can continue to be used in water-use planning and that policymakers need to focus on water resource management and protection. 展开更多
关键词 CHANGES in annual RUNOFF Climate change Human disturbance ATTRIBUTION RIVERS in China
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Annual Cycle and Interannual Variability in the Tropical Pacific as Simulated by Three Versions of FGOALS 被引量:4
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作者 俞永强 何杰 +1 位作者 郑伟鹏 栾贻花 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2013年第3期621-637,共17页
The seasonal cycle and interannual variability in the tropical oceans simulated by three versions of the Flexible Ocean-Atmosphere-Land System (FGOALS) model (FGOALS-gl.0, FGOALS-g2 and FGOALS- s2), which have par... The seasonal cycle and interannual variability in the tropical oceans simulated by three versions of the Flexible Ocean-Atmosphere-Land System (FGOALS) model (FGOALS-gl.0, FGOALS-g2 and FGOALS- s2), which have participated in phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5), are presented in this paper. The seasonal cycle of SST in the tropical Pacific is realistically reproduced by FGOALS-g2 and FGOALS- s2, while it is poorly simulated in FGOALS-gl.0. Three feedback mechanisms responsible for the SST annual cycle in the eastern Pacific are evaluated. The ocean-atmosphere dynamic feedback, which is successfully re- produced by both FGOALS-g2 and FGOALS-s2, plays a key role in determining the SST annual cycle, while the overestimated stratus cloud-SST feedback amplifies the annual cycle in FGOALS-s2. Because of the seri- ous warm bias existing in FGOALS-gl.0, the ocean-atmosphere dynamic feedback is greatly underestimated in FGOALS-gl.0, in which the SST annual cycle is mainly driven by surface solar radiation. FGOALS-gl.0 simulates much stronger ENSO events than observed, whereas FGOALS-g2 and FGOALS- s2 successfully simulate the observed ENSO amplitude and period and positive asymmetry, but with less strength. Further ENSO feedback analyses suggest that surface solar radiation feedback is principally re- sponsible for the overestimated ENSO amplitude in FGOALS-gl.0. Both FGOALS-gl.0 and FGOALS-s2 can simulate two different types of E1 Nifio events -- with maximum SST anomalies in the eastern Pacific (EP) or in the central Pacific (CP) -- but FGOALS-g2 is only able to simulate EP E1 Nifio, because the negative cloud shortwave forcing feedback by FGOALS-g2 is much stronger than observed in the central Pacific. 展开更多
关键词 annual cycle ENSO coupled GCM air-sea interaction
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THE IMPACT OF DIFFERENT PHYSICAL PROCESSES AND THEIR PARAMETERIZATIONS ON FORECAST OF A HEAVY RAINFALL IN SOUTH CHINA IN ANNUALLY FIRST RAINING SEASON 被引量:6
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作者 张旭斌 万齐林 +2 位作者 薛纪善 丁伟钰 李昊睿 《Journal of Tropical Meteorology》 SCIE 2015年第2期194-210,共17页
An ensemble prediction system based on the GRAPES model, using multi-physics, is used to discuss the influence of different physical processes in numerical models on forecast of heavy rainfall in South China in the an... An ensemble prediction system based on the GRAPES model, using multi-physics, is used to discuss the influence of different physical processes in numerical models on forecast of heavy rainfall in South China in the annually first raining season(AFRS). Pattern, magnitude and area of precipitation, evolution of synoptic situation, as well as apparent heat source and apparent moisture sink between different ensemble members are comparatively analyzed. The choice of parameterization scheme for land-surface processes gives rise to the largest influence on the precipitation prediction. The influences of cumulus-convection and cloud-microphysics processes are mainly focused on heavy rainfall;the use of cumulus-convection parameterization tends to produce large-area and light rainfall. Change in parameterization schemes for land-surface and cumulus-convection processes both will cause prominent change in forecast of both dynamic and thermodynamic variables, while change in cloud-microphysics processes show primary impact on dynamic variables. Comparing simplified Arakawa-Schubert and Kain-Fritsch with Betts-Miller-Janjic schemes, SLAB with NOAH schemes, as well as both WRF single moment 6-class and NCEP 3-class with simplified explicit schemes of phase-mixed cloud and precipitation shows that the former predicts stronger low-level jets and high humidity concentration, more convective rainfall and local heavy rainfall, and have better performance in precipitation forecast. Appropriate parameterization schemes can reasonably describe the physical process related to heavy rainfall in South China in the AFRS, such as low-level convergence, latent heat release, vertical transport of heat and water vapor, thereby depicting the multi-scale interactions of low-level jet and meso-scale convective systems in heavy rainfall suitably, and improving the prediction of heavy rainfall in South China in the AFRS as a result. 展开更多
关键词 numerical weather prediction heavy rainfall in South China in annually first raining season GRAPES model multi-physics parameterization ensemble prediction
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ANNUAL PRODUCTION OF FIVE SPECIES OF CHIRONOMIDAE (DIPTERA)IN HOUHU LAKE,A TYPICAL ALGAL LAKE(WUHAN,CHINA) 被引量:6
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作者 阎云君 梁彦龄 王洪铸 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1999年第2期112-118,共7页
Annual production and life cycle of five dominant species of Chironomidae (Chironomus plumosus, Cryptochironomus sp.,Tokunagayusurika akamusi, Procladius sp.,Clinotanypus sp.) were studied with samples collected month... Annual production and life cycle of five dominant species of Chironomidae (Chironomus plumosus, Cryptochironomus sp.,Tokunagayusurika akamusi, Procladius sp.,Clinotanypus sp.) were studied with samples collected monthly from April, 1996 to March, 1997 in Houhu Lake at four stations. Based on instar-frequency data,C. plumosus was univoltine, while the other four were bivoltine. Production rates in grams wet weight m?2a?1 calculated by the size-frequency method wereC. plumosus, 2.170;Cryptochironomus sp., 0.602;T. akamusi, 3.160;Procladius sp., 0.964;Clinotanypus sp., 0.390. Their P/B ratios were 3.9, 4.9, 4.4, 5.3 and 6.6, respectively. 展开更多
关键词 CHIRONOMIDAE annual production P/B ratio size-frequency method Houhu Lake
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Study on the Effects of Land Surface Heterogeneities in Temperature and Moisture on Annual Scale Regional Climate Simulation 被引量:4
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作者 曾新民 刘金波 +3 位作者 马柱国 宋帅 席朝笠 王汉杰 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2010年第1期151-163,共13页
The "combined approach", which is suitable to represent subgrid land surface heterogeneity in both interpatch and intra-patch variabilities, is employed in the BiOsphere/Atmosphere Transfer Scheme (BATS) as a land... The "combined approach", which is suitable to represent subgrid land surface heterogeneity in both interpatch and intra-patch variabilities, is employed in the BiOsphere/Atmosphere Transfer Scheme (BATS) as a land surface component of the regional climate model RegCM3 to consider the heterogeneities in temperature and moisture at the land surface, and then annual-scale simulations for 5 years (1988-1992) were conducted. Results showed that on the annual scale, the model's response to the heterogeneities is quite sensitive, and that the effect of the temperature heterogeneity (TH) is more pronounced than the moisture heterogeneity (MH). On the intraannual scale, TH may lead to more (less) precipitation in warm (cold) seasons, and hence lead to larger intraannual variability in precipitation; the major MH effects may be lagged by about 1 month during the warm, rainy seasons, inducing -6% more precipitation for some sub-regions. Additionally, the modeled climate for the northern sub-regions shows larger sensitivities to the land surface heterogeneities than those for the southern sub-regions. Since state-of-art land surface models seldom account for surface intra-patch variabilities, this study emphasizes the importance of including this kind of variability in the land surface models. 展开更多
关键词 regional climate model heterogeneities in temperature and moisture simulation on the annual scale sensitivity
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